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101.
地球内核快速旋转的发现与全球变化的轨道效应 总被引:3,自引:0,他引:3
科里奥利效应是产生内核快速旋转的主要原因。科氏力使上升物质向西漂移,下降物质向东漂移;造成地球外层自转减速,地球内层自转加速。所以,自旋体中的垂直运动可以产生大规模的水平运动——圈层差异旋转。地震波测量结果表明,内核旋转速度每年比地壳地幔快1°。对于一个内核差异旋转的地球,太阳辐射不仅形成地磁场的内外磁尾和地壳与内核的反向振动,而且影响核幔角动量交换和电磁耦合,从而控制了地球内能的释放,形成天文周期与地质旋回的一一对应关系。地球轨道和太阳轨道的全球变化响应,为太阳辐射量变化控制地球内能释放提供了证据 相似文献
102.
分析了表面活性剂和非水溶相有机污染物在水和土壤环境中的相互作用,以及表面活性的特性,解释了表面活性剂增效修复水和土壤环境中非水溶相污染物的机制。表面活性剂溶液通过增溶作用和增流作用,驱除地下水含水层中的非水相液体以及吸附于土壤颗粒物上的污染物,提高地下水和土壤中憎水性有机污染物的现场修复速率。增效修复效果依赖于临界胶束浓度(CMC)、污染物和表面活性剂的吸附特性、污染物的溶解性和土壤类型等。表面活性剂能增加化合物的溶解度,降低与水的界面张力,并形成乳液。 相似文献
103.
数值模式中长波辐射参数化方案的对比试验 总被引:2,自引:0,他引:2
应用一个简化的长波辐射参数方案,与郭晓岚-钱永甫模式原有长波辐射参数化方案进行了对比,分析了它们对100hPa,300hPa,500hPa,700hPa及地面的高度场、温度场、流场及气压场模拟结果的影响,发现不仅两者结果相当一致,而且与实测结果也符合很好。 相似文献
104.
105.
The roles of different mechanisms related to the tide-induced fronts in the Yellow Sea in summer 总被引:2,自引:0,他引:2
In summer, the Yellow Sea Cold Water Mass (YSCWM) is a stable water mass of low temperature lying at the bottom of the central Yellow Sea (YS). It is fringed by some typical tidal fronts, which separate deep, stratified water on the offshore side from the well-mixed, shallow water on the inshore side. Three striking fronts--Subei Bank Front (SBF), Shandong Peninsula Front (SPF), and Mokpo Front (MKF; a front off the southwestern tip of the Korean Peninsula)--have been iden- tified by various studies from both satellite observations and model results. Tide plays an important role in the formation and maintenance of these fronts. However, it is still a matter of debate as to the roles these two kinds of mechanisms of upwelling and tidal mixing play, and how importance they are in the maintenance processes of the above three fronts. Basing a nested high-resolution model HYCOM (the Hybrid Coordinate Ocean Model), this study focuses on the different mechanisms of tidal effects on the thermal fronts in the YS in summertime. Through comparative experiments with and without tidal forcing, the results indicate that the MKF is mainly driven by tide-induced upwelling. For the SPF, tidal mixing is the dominant factor, when lower cold water is stirred upwards along the sloping topography of the western YS. Meanwhile, the combined effect of upwelling and tidal mixing is the main cause of the formation of the SBF. Diagnostic analysis of thermal balance shows that horizontal nonlinear advection induced by strong tidal currents also contributes to the thermal balance of frontal areas. 相似文献
106.
青藏高原北侧地区干湿年夏季垂直环流差异的对比分析及青藏高原的热力影响 总被引:30,自引:2,他引:30
为了分析西北干旱的形成原因,本文首先利用高原北侧地区5站历年夏季的降水量资料等,制定了该区的干湿标准,划分了历年夏季的干湿等级。接着又利用ECMWF的格点资料等对比分析了该区干湿年夏季间垂直环流的差异,也探讨了青藏高原地面热状况与高原北侧干湿状况的联系。其主要结论是:1)文中制定的以降水标准差为判据的干湿标准适合西北干旱区;2)高原北侧干湿年夏季间在高原北侧和高原上的垂直环流存在明显差异;3)青藏高原地面热状况与上列差异有关,也即青藏高原的热力作用是西北干旱的重要成因之一。 相似文献
107.
108.
基于塔克拉玛干沙漠腹地面积最大的天然孤立绿洲达理雅博依2015年1月—2016年2月太阳总辐射观测资料,运用H.L.Penman经验公式模拟计算了该地区2015年逐日总辐射累计量,模拟值与实测值的误差分析显示:本气候学方法成功模拟了沙漠腹地总辐射的年内变化趋势。使用模拟值估算得到达理雅博依绿洲2015年太阳总辐射累计量约为5 332.23 MJ·m-2。又以相同方法模拟了塔中气象站2015年3—5月总辐射变化,结果较达理雅博依的模拟更接近实测值,说明本模拟在塔克拉玛干沙漠腹地不同地点结果有效。 相似文献
109.
One of the main limitations to the sensitivity of the infrared camera ISOCAM on-board the Infrared Space Observatory (ISO)
comes from responsivity variations and glitches caused by the impacts of charged particles in photo-detectors. Glitch rate
measurements, glitch properties and removal methods have already been addressed during the first ISO detector workshop(Madrid,
1998) and published in a special issue of Experimental Astronomy. It appeared that glitch rate and most of glitch properties
could be reproduced by Monte-Carlo simulations. This is very interesting in order to predict before launch the effect of charged
particles in photo-detectors operated in space. This paper presents results of Monte-Carlo simulations of radiation effects
on ISOCAM detectors. Glitch rates, spatial and energetic properties of glitches have been computed and are compared with measured
values.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
110.
L.Scheck M. A.Aloy J. M.Martí J. L.Gómez E.Müller 《Monthly notices of the Royal Astronomical Society》2002,331(3):615-634
We study the influence of the matter content of extragalactic jets on their morphology, dynamics and emission properties. For this purpose we consider jets of extremely different compositions, including pure leptonic and baryonic plasmas. Our work is based on two-dimensional relativistic hydrodynamic simulations of the long-term evolution of powerful extragalactic jets propagating into a homogeneous environment. The equation of state used in the simulations accounts for an arbitrary mixture of electrons, protons and electron–positron pairs. Using the hydrodynamic models, we have also computed synthetic radio maps and the thermal bremsstrahlung X-ray emission from their cavities.
Although there is a difference of about three orders of magnitude in the temperatures of the cavities inflated by the simulated jets, we find that both the morphology and the dynamic behaviour are almost independent of the assumed composition of the jets. Their evolution proceeds in two distinct epochs. During the first one, multidimensional effects are unimportant and the jets propagate ballistically. The second epoch starts when the first larger vortices are produced near the jet head, causing the beam cross-section to increase and the jet to decelerate. The evolution of the cocoon and cavity is in agreement with a simple theoretical model. The beam velocities are relativistic ( Γ ≃4) at kiloparsec scales, supporting the idea that the X-ray emission of several extragalactic jets may be due to relativistically boosted CMB photons. The radio emission of all models is dominated by the contribution of the hotspots. All models exhibit a depression in the X-rays surface brightness of the cavity interior, in agreement with recent observations. 相似文献
Although there is a difference of about three orders of magnitude in the temperatures of the cavities inflated by the simulated jets, we find that both the morphology and the dynamic behaviour are almost independent of the assumed composition of the jets. Their evolution proceeds in two distinct epochs. During the first one, multidimensional effects are unimportant and the jets propagate ballistically. The second epoch starts when the first larger vortices are produced near the jet head, causing the beam cross-section to increase and the jet to decelerate. The evolution of the cocoon and cavity is in agreement with a simple theoretical model. The beam velocities are relativistic ( Γ ≃4) at kiloparsec scales, supporting the idea that the X-ray emission of several extragalactic jets may be due to relativistically boosted CMB photons. The radio emission of all models is dominated by the contribution of the hotspots. All models exhibit a depression in the X-rays surface brightness of the cavity interior, in agreement with recent observations. 相似文献